Pressure fluid motor



Nov. 30,- 1937.

E. G. GARTIN PRESSURE FLUID MOTOR v Filed Nov. l, 1934 Nov. 30, 1937. E. G. GARTIN 2,100,541

PRESSURE FLUID MOTOR Filed Nov. l, 1954 2 Sheets-Sheet 2 v, '11( az, l@ t i Patented Nov. 30, 19.37

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PRESSURE rLUn) Mo'roa Elmer G.- Gartin, Claremont, N. H., assigner to Sullivan Machinery Company, a corporation of Massachusetts Application November l, 1934, Serial No. 751,014 i3 claims. (c1. 12in-12) Y This invention relates to pressure luid motors, and more particularly to improved blow-varying means for a pressure fluid motor of the reciprocating piston type especially designed for use in impact tools.

An object of this invention isV to provide an improved pressure fluid motor having embodied therein improved blow-varying means. Another object is to provide an improved pressure iluid 1o motor of the impact type especially designed for use in impact tools having improved Vmeans to vary the force of the blow of the piston so that a heavy, medium or light blow may be transmitted'to the working implement of the impact tool.l Yetanother object is to provide in a pressure uid motor of the above character improved blow-varying means associated with the valve mechanism for changing the throwing action of the valve thereby to vary the piston blows. 20 These and other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there is shown for purposes of illustration one form which th invention may assume in practice.

In these' drawings- Fig. l is a longitudinal section through an impact tool having embodied therein the illustrative form of the improved pressure fluid motor, the view taken more or lessin the planes of linel-I of Fig. 3, with certain parts out of the plane of said section shown as if they were cut thereby.

Fig. 2 is a View similar to Fig. l showing the moving motor parts in a different position.

Fig. 3 is a cross sectional view through elements of the improved blow-varying means.

Fig. 4 is a cross sectional View showing the motor cylinder in end elevation.

Figs. 5 and 6 are views similar to Fig. 3 showing the blow-varying means in different adjusted positions.

Fig. 7 is a detail vertical sectional view, partially in elevation, taken on line of Fig. 5.

Fig. 8 is a detail vertical sectional View, partially in elevation, taken on line 8-8 of Fig. 6.

Fig. 9 is a detail sectional view taken on line 9-9 of Fig. 3.

In this illustrative embodiment of the invention the improved blow-varying means is shown embodied in an impact tool having a hammer motor of the pressure uid actuated, reciprocating hammer type, although it will be evident that the invention may be incorporated in mo- 555 tors of various other types. This hammer motor comprises a cylinder l having a bore 2 containing a reciprocatory hammer piston 3. This piston has a front striking nose 4 adapted to deliver impact blows through a tappet 5 to the shank 6 of a working implement. The tappet 5 is guided in a bore 1 formed within a chuck member 8 within which the working implement t is suitably supported. Arranged in a bore 9y formed in a rear head member lll suitably secured to the rear end of the motor cylinder is a valve chest `comprising a valve box Il having face abutting engagement with a valve box cover i2, the latter in this instance forming the rear head plate for the motor cylinder. The rear head member i@ is provided with a pressure fluid chamber `l3 to which pressure fluid is supplied through a passage I4 from any suitable pressure fluid source. Formed in the valve box ll is a valve chamber l5 having reciprocable therein an automatic pressure fluid actuated uid distributing valve 46,' herein of the well known differential sleeve type. This valve has a sleeve-like body, an imperforate rear end wall and enlarged end flanges l1 and I8 fitting the valve chamber bore and forming an annularA groove I9 between the anges surrounding the valve body. The valve is guided on a cylindrical projection l2| extending within the interior of the valve body and formed integral with the rear head plate I2, and the interior of the valve is vented to atmosphere through a vent passage 22 formed in the head plate. Surrounding the valve chamber at itsforward end is an annular recess 23, while formed at the upper end of the valve chamber is an annular groove 24, the grooves 23 and 24 having formed therebetween an annular groove 25. The extreme upper Yend of the valve chamber is vented to atmosphere through a vent passage 25. Connecting the forward end of the valve chamber directly to the rear end of the cylinder bore is a series of longitudinal passages 2lv formed in the headplate I2, while connecting the intermediate groove 25 with the forward end of the cylinder bore isa passage 28. Pressure fluid is supplied from the supply chamber I3 to the groove 23 through a longitudinal supply passage 29.. The groove 24 is vented to atmosphere through an exhaust passage 30. Communicating-with a recess 3| in the valve box ll at the rear end of the valve chamber is a passage 32 formed in the valve box and valve box cover and communicable with the cylinder bore in a manner that will later be described. The cylinder bore is provided intermediate its ends with a pair of piston controlled free exhaust ports 34.

When the parts are in the position shown in Fig. l, pressure uid may flow through passage I4, chamber I3, passage 29, groove 23 through the valve chamber past the forward surface of the valve body and through the series of longitudinal passages 21 to the rear end of the cylinder bore, the pressure fluid acting on the rear pressure area of the hammer piston to drive the latter forwardly to eifect its working` stroke, i. e'. to deliver an impact blow through the tappet 5 to the shank 6 of the working implement. At this time the forward end of the cylinder bore is connected to exhaust through the free exhaust ports 34. As the hammer piston travels forwardly it covers the free exhaust ports 34, and upon continued forward movement the rear edge ofthe piston overruns the mouth of the passage 32, thereby admitting pressure Vfluid from the rear end of the cylinder bore through the passage 32 to the recess 36 communicating with the rear end of the valve chamber at the upper side of the valve to throw the valve forwardly from the position shown in Fig. 1 to the position shown in Fig. 2, against the opposing pres-sure acting on the forward pressure area of the valve, the rear pressure area of the valve being substantially larger than the forward pressure area due to theV interior venting of the valve through vent passage 22.

Y When the parts are in the position shown in Fig. 2,

pressure fluid may flow from chamber I3 through passage 2S, groove 23, past the exterior groove I9 on the valve and thence through groove 25 and passage 28 to the forward end of the cylinder bore, the pressure fluid acting on the front pressure area of theV piston to drive the latter rearwardly to effect its retractive stroke. At this time the rear end of the cylinder bore is open to exhaust through the free exhaust ports 34, and as the hammer piston moves rearwardly these exhaust ports are closed. Upon continued rearward movement of the motor piston, the forward edge of the piston overruns the exhaust ports 34, connecting the forward end of the cylinder bore to exhaust, while the pressure fluid Y32 is communicable.

trapped in theY rear endY of the cylinder bore is compressed by the piston. VThis compression pressure acts on the forward pressure area of the valve, throwing the latter rearwardly from the position shown in Fig. 2 to the position shown in Fig. 1 against the opposingreduced pressure at the upper end of the valve chamber, the latter being vented through the vent passage 26. These operations are repeated in rapid succession during normal operation of the motor. Y

Now referring to the improved blow-varying means, it will be noted that the valve box II and valve box cover I2 are held againstrotative movement in the bore 9 by a dowel pin 40 engagingrone of a series of circumferentially spaced grooves, herein numbered 4I, 42 and 43, formed on the exterior periphery of the valve box and valve box cover. Also formed on the valve box and valve box cover are three passages 44, 45 and 46 communicable with the passage 28, while formed in thecylinder are three valve throwing passages 47, 48 and 49 with which the passage These passages respectively communicate with the cylinder bore through ports 5B, 5I and 52 suitably spaced with respect to each other along the length ofthe cylinder bore in the manner shown. So that the exhaust passage 3l! will at all times communicate with the atmosphere, the valve box is provided with municates with -the supply passage 28.

an arcuate slot 53 with which the passage 30 communicates, and this slot 53 at all times communicates with an exhaust port 54. The head member I0 has ventV passages 55 with which the vent passage 22 is communicable in the dilferent positions of the valve box cover with respect thereto. Y

When the parts'are inthe position shown in Fig. 3, the pressure fluid motor operates as above described in'regard to Figs 1 and 2 with the motor piston delivering a relatively hard, full stroke blow through the tappet to the shank of the working implement, the forward port 50 communicating through the longest throwing passage 49 with the passage 32 at that time. When it is desired to lessen the intensity of the blow delivered by the motor, that is when it is desired to deliver a relatively light blow through the tappet 5 to the shank of the working implement 6, the operatorchanges the position of they valve box II by removing the head member I and dowel 40 and rotating the valve box and cover with respect to the cylinder until the dowel is in registry with the dowel groove 43 and thereafter reinserting the dowel and replacing the head member to hold the parts in the position shown in Figs. 6 and 8, with the dowel engaging the groove 43 on the valve box and cover. At this time communication of the valve throwing passages 48 and 49 with the cylinder bore is cut off by the forward face of the valve box cover, blanking off the upper ends of these bores while the relatively short throwing passage 4'! communicates through the port 52 with the cylinder bore, and the passage 44 communicates with the supply passage 28. Thus during operation of the motor the port 52 sage Y4'! is opened by the rear edge of the piston substantially sooner than during full piston stroke, as above described, so that the distributing valve is thrown more quickly, resulting in ofthe shortest Vvalve throwing pasa quicker return of the piston and a piston stroke with a lighter blow. When it is desired to adjust the blow-varying mechanism to a medium position, the parts are adjusted, as shown inl Figs. 5 and 7, withthe dowel engaging the intermediate groove 42, and at Vthis time the medium length passage 48 communicates through the central port 5I with the cylinder bore midway between the ports 5U and-52, and the passage 45 com- As a result, the action of the valve is materially quicker than when the port 50 is used, but slower than during the use of the upper port 52. t will thus be seen that by varying the points of communication of the valve throwing passage with the cylinder bore, it is possible to change the action of the distributing valve so that the same may be either rapid, mediumY or slow, and due to the variation ln the timing of the distributing valve, the piston blow is at the same time varied. It will also be noted that by changing the piston somewhat.

blow simply by changing the position of the 1 valve box and cover, a blow-varying mechanism is provided which is extremely simple in design. It will further be evident that by the provision of the dowel engaging the grooves on the valve box and cover, it is impossible for an inexperienced operator to incorrectly place the parts. It is, however, readily conceivable that the valve box may be so constructed as to permit its shifting from one position to another withoutrequiring a partial dismantling' of any portion of the motor, for instance by a suitable lever secured to the valve box and operating through a slot in fel) a bore, Aa hammer Vpiston reciprocable therein, av

uid actuated fluid Vdistributing valve having a throwing area, Aa valve chest having cooperating.

parts `providing a valve chamber in which said Valve is arranged, passages controlled by said valvefor conducting pressure fluid to said cylinder bore, a plurality of throwing passages Aconflmunicating with the cylinder bore, respectively,

Vthrough ports .spaced longitudinally of the .cylinder, and adjustable means including at least a part of'said valve chest adjustable relative to said cylinder for selectively connecting said throwing passages in communication with said valve throwing .area to effect throwing of the valve at different points in the piston stroke thereby to vary thevalve actuation and the blow of the piston.

.2. In a pressure fluid motor, a Ycylinder having a bore, a hammer piston reciprocable therein, aV

uid actuated fluid distributing valve having a throwing area, a valve chest having cooperating parts providing a valve chamber in which said valve is arranged, passages controlled by said valve for conducting pressure fluid to said cylinder bore, a plurality of throwing passages communicating with the cylinder bore, respectively, through ports spaced longitudinally of the cylinder, and adjustable means including at least a part of said valve chest rotatable relative to said cylinder about an axis alined with the cylinderV bore -axisfor selectively connecting said throwing passages in communication with saidvalve throwing jarea Vto eiect throwing lof the valve at diiferent points in the piston stroke thereby to vary the valve actuation and the blow of the piston.

3. In a pressure fluid motor, acylinder having a bore, a piston vreciprocable therein, a valve `box having a valve chamber, a huid vactuated fluid distributing valve in said valve chamber and having a throwing area, passages controlled by said Valve for conducting pressure fluid to said cylinder bore, a plurality of throwing passages cornmunicating with the lcylinder bore, respectively, through ports spaced longitudinally of the cylinder, and means for varying the piston blow including lsaid 4valve box, said valve box adjustable into different predetermined positions with respect to the cylinder and having passage means for selectively connecting said throwing passages into communication with said valve throwing area to effect throwing of the valve at different points in the piston stroke thereby to vary the Valve actuation and the blow f the piston.

4. In a pressure fluid motor, a cylinder having a bore, a piston reciprocable therein, a valve chest having a valve chamber, passages for conducting pressure fluid from the valve chamber to the cylinder bore, a valve in said valve chamber for controlling said passages and having a throwing area, a plurality of throwing passages in the cylinder communicating with the cylinder bore, respectively, through ports spaced longitudinally of the cylinder bore, said valve chest being rotatable into different positions with'respect tothe cylinder and having ya passage communicating with said valve throwing 'area andadapteditoregister-selectively with "said throwing passages in the cylinder to .supply lpressurefluid'fromthe cylinder bore topthe valve'throwing area to 'throw the valve at different points :in the .piston stroke to vary the piston blow, and means dor :holding the Avalve chest'inzits diiferent adjusted positions.

5. Ina pressure fluid motor, Va cylinder having abore, a piston reciprocable therein, a valve chest having a valve chamber, passages for conducting pressure ifluid from the valve chamber ttoY `the cylinder bore, avalvelin said valve chamberffor cont-rolling said passages and having af throwingV v1 area, a plurality of throwingY passages .inthe cylinder communicating with the cylinder bore,.respectively, through ports spaced longitudinallyof the cylinder'bore, said valve chest being rotatable into different positions with respect Ytothe cylinder landhaving a passagecommunicating :with Said valve throwing area andladapted to Aregister selectively with said throwing passagesin the cylinder to supply pressure fluid `fromthe :cylinder bore ito the valve throwing area '-to throw the Valve yat different Vpoints in thepiston stroke to vary the piston blow, and means for holdingithe valve chest in its different adjusted ypositions. including interlocking ymeans connected to 'said valve chest. v z

6. In a pressure fluid motor, a cylinder having a bore, a piston reciprocabl'eithereimia'valve chest having a valve chamber, passages for conducting pressure fluid from'the valve chamber to the cylinder bore, a vvalve in'said'valve chamber for controlling said passages and having a throwing-area,

Ya kvplurality of throwing passages in the cylinder communicating with the cylinder bore, respectively, through ports spaced longitudinally ofrthe cylinder bore, said valve chest being rotatable into diierent positions with respect Ito the cylinder and Ahaving a zpassage communicating with .said valve throwing area and adapted to register select-ively'with said throwing vpassages -in the cylinder tosupply pressure uid from Vthe cylinder bore to the valve throwing v.area to throw the Valve at different points in the .piston stroke to vary `the piston blow, and means vfor holding the valve chest in its different adjusted positions including a dowel pin held ystationary with respect to the cylinder and .grooves on `the valve chest with which said dowel pin is selectively engageable. f

7. In a pressurefluid motor, .a cylinder having a bore, a hammer pistonreciprocable therein, a fluid actuated uid distributing l.valve having a throwing area and an opposed area, .a valve chest having cooperating parts providing a valve-chamber in which said valve is arranged, passages controlled by vsaid valve for conducting pressure fluid to the opposite ends of the cylinder bore, venting means `for said opposed area, a plurality of separate throwing passages of different lengths communicating with the cylinder bore, respectively, through ports spaced longitudinally of the cylinpart of said valve chest adjustable relative to said cylinder for selectively connecting said throwing in communication with .said valve f der, and adjustable means including at least 'aiV .65 Y

parts providing a valve chamber in which said valve is arranged, passages controlled by said Y valve for conducting pressure uid to the opposite ends of the cylinder bore, aV plurality of separate throwing passages of diierent lengths communieating with the cylinder bore, respectively, through ports spaced longitudinally of the cylinder, and adjustable means for varying the blow of the hammer piston including at least a part of said valve chest having a passagecommunicating With the throwing area onlthe valve and selectively communicable with said throwing passages to eiect throwing of the valve at different points in the piston stroke thereby to vary the volume of pressure fluid supplied to the ends of the cylinder bore'.

9. In a pressure fluid motor, a cylinder having a bore, a hammer piston recprocable therein, `a valve box having a valve chamber, a fluid actuated fluid distributing valve having a throwing area, passages controlled by said valve for conducting pressure fluid to the opposite ends of the cylinder bore, a plurality of separate throwing passages of different lengths communicating with the cylinder bore, respectively, through ports spaced longitudinally of the cylinden'said valve boX adjustable into different predetermined positionsv with respect to the cylinder-for bringing said throwing passages selectively into communication with said valve throwing area.

10. In a pressure fluid motor, a cylinder having a bore, a piston recprocable therein, a valve chest having a valve chamber, a iluid actuated uid distributing valve in said valve chamber and having va throwing area, passage means controlled by said valve for conducting pressure fluid to said cylinder bore, throwing passage means respec-V tively communicating with the cylinder bore through ports spaced longitudinally of the cylinder, said portsV controlled by said piston, and means for varying the blow of said piston .including said valve chest, said valve chest ,adjustable into diierent predetermined positions with respect to the cylinder and having passage means for selectively connecting said ports through their respective throwing passage means into communication with said valve throwing area to effect Y throwing of the valve at diierent points in the piston stroke thereby torvary the valve actuation and the blow of said piston.

l1. In a pressure uid motor, a cylinder having a bore, a piston recprocable therein, a valve chest having a valve chamber, passage means for conducting pressure fluid from said valve chamber to the cylinder bore, a valve in said valve chamber for controlling said passage means and having a throwing area, throwing passage means in the cylinder communicating with the cylinder bore respectively through ports spaced longitudinally of the cylinder bore, said ports controlled by said piston and said valve chest'being adjustable into different predetermined positions with respect to said cylinder and having passage meansrcommunicatingwith said valve throwing area and adapted to register selectively with said different throwing passage means in the cylinder to supply pressure fluid vfrom the cylinder bore to the' valve throwing area to throw the valve at different points in the piston-stroke to vary the piston blow,

Vand releasable means Vfor holding said valve chest in its different adjustedrpostions.V .A

12. In a pressure 'fluid motor, a cylinder having a bore; a hammer piston recprocable therein, uid distribution means for supplying pressure fluid to said cylinder including a fluid actuated` fluid distributing valve having a throwing area,

and passage means controlled by said valve for conducting pressure fluid to said cylinder bore,

throwing passage means respectively communi- Veating with the cylinder bore through ports spaced longitudinally `of the cylinder, said'ports controlled by said piston, and means for varying the blow of said hammer piston including a part in which at least a portion of said uid distribution means is-formed, said part adjustable into diierent positions with respect to the cylinderand having passage means forrselectively connecting said ports Y through their respective throwing passage means into communication with said valve throwing area to effect throwing of the valve at different points in the piston stroke thereby to vary the Valve actuation and the blow of the piston.

13. In a pressure fluid motor, a cylinder having a bore, a hammer piston recprocable therein, fluid distribution means forsupplying pressure fluid to said cylinder includingY a fluid actuated fluid distributing Vvalve having a throwing area, and passage means controlled by said valve including uid supply passages for conducting pressure fluid to said cylinder bore, throwing passage meansrespectively communicating with the cylinder bore through-ports spaced longitudinally of the cylinder, said ports controlled by said piston, and means for Varying theblow of said hammer piston including a part in'whichvat least one fluid supply passage is formed, said part adjustable into different positions with Vrespectrto the cylinder and having passage-means for selective-V ly connecting said ports through their respective throwing passage means in communication with Ysaid valve throwing area Yto effect throwing of 

